Fix MSE GC, make it less aggressive, more spec-compliant

media/filters/source_buffer_stream.h

Index: media/filters/source_buffer_stream.h
diff --git a/media/filters/source_buffer_stream.h b/media/filters/source_buffer_stream.h
index 85ff8d00a919b86461243ef3ec6ad82a8ea201ab..be1f6e0f115a1d08ffa96ccc6e9471e097c94103 100644
--- a/media/filters/source_buffer_stream.h
+++ b/media/filters/source_buffer_stream.h
@@ -90,6 +90,10 @@ class MEDIA_EXPORT SourceBufferStream {
   void Remove(base::TimeDelta start, base::TimeDelta end,
               base::TimeDelta duration);
 
+  // Frees up space if the SourceBufferStream is taking up too much memory.
+  // |media_time| is current playback position.
+  bool GarbageCollectIfNeeded(DecodeTimestamp media_time);
+
   // Changes the SourceBufferStream's state so that it will start returning
   // buffers starting from the closest keyframe before |timestamp|.
   void Seek(base::TimeDelta timestamp);
@@ -150,19 +154,20 @@ class MEDIA_EXPORT SourceBufferStream {
  private:
   friend class SourceBufferStreamTest;
 
-  // Frees up space if the SourceBufferStream is taking up too much memory.
-  void GarbageCollectIfNeeded();
-
   // Attempts to delete approximately |total_bytes_to_free| amount of data
   // |ranges_|, starting at the front of |ranges_| and moving linearly forward
   // through the buffers. Deletes starting from the back if |reverse_direction|
-  // is true. Returns the number of bytes freed.
-  size_t FreeBuffers(size_t total_bytes_to_free, bool reverse_direction);
+  // is true. |media_time| is current playback position.
+  // Returns the number of bytes freed.
+  size_t FreeBuffers(size_t total_bytes_to_free,
+                     DecodeTimestamp media_time,
+                     bool reverse_direction);
 
   // Attempts to delete approximately |total_bytes_to_free| amount of data from
   // |ranges_|, starting after the last appended buffer before the current
-  // playback position.
-  size_t FreeBuffersAfterLastAppended(size_t total_bytes_to_free);
+  // playback position |media_time|.
+  size_t FreeBuffersAfterLastAppended(size_t total_bytes_to_free,
+                                      DecodeTimestamp media_time);
 
   // Gets the removal range to secure |byte_to_free| from
   // [|start_timestamp|, |end_timestamp|).